1. Field of the Invention
The present invention relates to a lithium cell. Particularly, the present invention relates to improvement of a positive electrode active material of the lithium cell.
2.Description of the Related Art
A lithium cell in which copper oxide is used as a positive electrode active material (hereinafter, sometimes referred to as "Li/CuO" for abbreviation) has been heretofore proposed as a large capacity density lithium cell. For example, reference can be made to Broussely M., Jumel Y. and Gabano J. P. (1977) 152nd Electrochemical Society Meeting, Atlanta (Abstract No. 9 (p. 33)).
However, the closed circuit voltage of the above Li/CuO is as low as about 1.5 V.